Clarrie Hall Dam Reopened following major upgrade
Council's $7.3 million upgrade of Clarrie Hall Dam was unveiled on 22 May 2014 by the NSW Minister for Natural Resources, Lands and Water, the Hon. Kevin Humphries, MP. By widening and extending the spillway and raising the dam's wave wall, it now meets the revised standards of the New South Wales Dam Safety Committee and provides greater control of extreme flood levels in the dam.
Clarrie Hall Dam Reopening Photos (2.84mB PDF)
For further information on the upgrade, see Clarrie Hall Dam Spillway Upgrade.
About the Dam
Clarrie Hall Dam is located on Doon Doon Creek - a tributary of the South Arm of the Tweed River, some 15 kilometres south-west of Murwillumbah. The dam has a catchment area of 60 square kilometres and a usable storage capacity of 15,000ML.
The primary function of the dam it to store drinking water for the Tweed. When required, water is released from the dam’s intake tower and flows down the Tweed River. At Bray Park, it is drawn off and treated at a state-of-the-art treatment plant to ensure suitable drinking quality.
|Full Capacity Water Level||61.5m AHD|
|Current Water Level||61.5m AHD|
|Current Capacity||100% (External sales allowed)|
|Last Updated||23 December 2015|
Algae Alerts (as at 12 October 2015)
Current Algae Alerts for Clarrie Hall Dam (including Crams Farm): Nil
Current Algae Alerts for Bray Park Weir: Nil
Clarrie Hall Dam is open to the public from 7am-5pm (6pm during daylight savings) all year round. Access is via security gates at Crams Farm on Clarrie Hall Road.
Clarrie Hall Dam is set among picturesque forest. While the primary function of the dam is to provide storage for Tweed's water supply, it also is a great area for picnics and barbecues, bush walking, sports fishing and bird watching.
Facilities at Clarrie Hall Dam include toilets, picnic areas and electric barbecues.
Crams Farm Reserve has an extensive area for recreation, toilet facilities and two large sheltered areas, the Dairy and a shelter for the general public.
Signage at Clarrie Hall Dam displaying the permitted land and water based activites, facilities provided and restrictions (251kB JPG)
Beyond the security gates, the Dairy is the first sheltered area on the left. It has picnic tables and can be booked during opening hours for exclusive use. Exclusive use means the exclusive use of the Dairy and kitchenette (including power and water) and the freedom to use the rest of Crams Farm with the general public. Please refer to Council's fees and charges for hire fees. www.tweed.nsw.gov.au/FeesAndCharges
Crams Farm - General Area
The second sheltered area has electric barbecues and picnic tables. This area is available on a 'First In Best Dressed' basis and cannot be cordoned off for exclusive use.
The grassed area at Crams Farm can be booked for a maximum of three hours for social gatherings, including wedding ceremonies. Refer to Council's fees and charges for hire fees. www.tweed.nsw.gov.au/FeesAndCharges
To book and for booking conditions, please complete either the Casual Park Hire Application Form - Wedding Ceremonies (71kB PDF) or Casual Park Hire Application Form - Other (not Weddings) (59kB PDF).
Please note, this permit does not give you exclusive use of any of the public areas. Under no circumstance, is roping or cordoning off of an area permitted. So to avoid disappointment, we recommend that you or a member of your gathering aim to arrive at the location early.
Dam SafetyTweed Shire Council, as the dam owner, is responsible for safety at Clarrie Hall Dam. Dams are regulated by NSW Dam Safety Committee under the guidance of the Australian National Committee on Large Dams and the Dam Safety Act 1978. Council regularly monitors and reports on the condition of the dam under these regulations.
Clarrie Hall dam is extremely safe structurally.
While the current spillway capacity is deemed sufficient to pass a extreme flood event, there is still a small risk of failure in the unlikely event of an earthquake or other catastrophic occurrence. Council has a Dam Safety Emergency Plan (1.41mB PDF). The plan shows who will be affected and sets out how Council will communicate information so the public is protected and those directly impacted are evacuated. The plan is activated during floods when certain dam levels are reached, or immediately if other events occur. Council provides education to downstream residents so they know how the Dam Safety Emergency Plan is managed. See Emergency Management.
The dam was designed and constructed by the then NSW Department of Public Works for Tweed Shire Council. Construction was completed in 1983.
Clarrie Hall Dam consists of a concrete-faced rock-fill embankment, a concrete-lined spillway and intake and outlet works constructed on a foundation of very hard/strong rhyolite rock (of volcanic origin).
The rock-fill embankment comprises about 160,000 cubic metres of fill, is 43 metres high and has a 6-metre-wide crest that is 175 metres long.
The crest's upstream and downstream slopes are 1V to 1.3H. The upstream slope is covered by a 300mm thick concrete face slab, which connects at the top to a wave wall along the embankment crest. The bottom of the face slab is tied to the embankment's upstream concrete toe slab, which also acts as the grout cap. A grout curtain, comprising a single line of holes, is located under the slab.
The embankment is constructed from hard rhyolite rock fill, which is free-draining except for a 4-metre-wide semi-permeable zone located immediately underneath the upstream face. Seepage through the embankment is measured by a weir located at the downstream toe.
The present full supply level (ie top water level) of the dam is RL61.5m (AHD), which is 7 metres below the embankment wave wall crest level (ie the top of the wave wall on the dam crest).
The spillway is an ungated concrete chute with ogee weir and flip bucket located on the left abutment. The spillway chute and approach area between the dam toe slab and spillway crest are fully lined and have 6 to 8-metre-high walls. The spillway chute is 110 metres long. The spillway crest is 22 metres wide and the chute width narrows to 12 metres for much of its length. The spillway was designed to pass the original probable maximum discharge of 590 cumecs.
The intake/outlet system consists of a 34-metre-high, 4-metre outside diameter reinforced concrete tower of the wet-well type, situated on a tower base structure at the head of the outlet tunnel beneath the right abutment.